A breather apparatus is provided in a gear case housing a gear box such as a transmission. The apparatus releases the air from the gear box so that both the temperature and pressure of air can be controlled to be normal. In a vehicle driven by a motor such as an electric vehicle, a hybrid vehicle and the like, an additional breather apparatus is also provided in a motor case housing a motor so that the temperature and pressure of air in the motor case can be prevented from rising undesirably.
A conventional vehicle driven by a motor has employed a breather for a gear case and a motor case respectively, thereby causing an increase in the dimensions of each case. However, a vehicle with a fuel cell, which needs to house a super charger and a large radiator in an engine room where gear and motor cases are also installed, has required each case to be compact as much as possible.